The present invention relates to a branch joint box into which connectors of a wiring harness for a motor vehicle are inserted for connection so as to join a circuit by branching.
In a branch joint box used for joining a wiring harness for a motor vehicle to various electrical parts by branching, branch joint points are concentrated at one spot so as to reasonably and economically join a circuit by branching. In response to rise of density of wires of the wiring harness, various types of branch joint boxes have been developed.
In one of these known branch joint boxes, in case the branch joint box is assembled by preliminarily incorporating a male connector into the branch joint box and a female connector connected to a wiring harness is coupled with the male connector at an assembly line of motor vehicles, a lock cover for effecting double locking of the male and female connectors is mounted on the branch joint box in advance at an assembly line of branch joint boxes.
It is to be noted that the terms "male connector" and "female connector" are, respectively, used in this specification to mean a "connector having male terminals" and a "connector having female terminals" irrespective of their configurations.
For example, as shown in FIG. 1, a pair of dovetails 3a provided on opposite side faces of a unit 3 having a male connector 2 are, respectively, inserted from below into a pair of dovetail grooves 1b formed on opposite sides of a hollow 1a of a branch joint box 1 and a boss 3b provided on a rear face of the unit 3 as shown in FIG. 2 is brought into engagement with a slot 1c of a rear wall of the hollow la of the branch joint box 1 such that the unit 3 is secured to the branch joint box 1. Meanwhile, a lock cover 4 is provided on the unit 3 so as to be opened and closed through a thin hinge portion 4a integrally molded with the lock cover 4 as shown in FIG. 2.
As shown in FIG. 3, a dummy cover connector 5 is fitted into the male connector 2 of the unit 3 so as not to be closed during transport, etc. of the branch joint box 1 prior to mounting of the branch joint box 1 on a motor vehicle. At this time, in order to hold the lock cover 4 at an open position, not only a front face of the dummy cover connector 5 is brought into contact with a locking projection 4b of the lock cover 4 so as to retain the locking projection 4b but a hooked piece 3c of the unit 3 is brought into engagement with a recess 4c of the lock cover 4.
The branch joint box 1 is assembled in the above described state. Thus, when the branch joint box 1 is mounted on a motor vehicle, the dummy cover connector 5 is drawn out of the male connector 2 and then, a female connector 7 connected to a wiring harness 6 is fitted into the male connector 2. Subsequently, when the lock cover 4 is pushed to a closed position, the locking projection 4b of the lock cover 4 is brought into engagement with a recess 7a of the female connector 7 as shown in FIG. 2 so as to lock the female connector 7 at the fitting position. At the same time, a hooked piece 4d of the lock cover 4 is brought into engagement with a recess 3d so as to hold the lock cover 4 at a closed position.
However, in the above described arrangement of the known branch joint box 1, since the dummy cover connector 5 is required to be provided additionally, the number of components increases, thereby resulting in increase of the number of control steps of the components. Meanwhile, since the female connector 7 cannot be fitted into the male connector 2 unless the dummy cover connector 5 is drawn out of the male connector 2, the number of operational steps increases. Furthermore, there is such a risk that the lock cover 4 is closed inadvertently before the female connector 7 is fitted into the male connector 2 after the dummy cover connector 5 has been drawn out of the male connector 2. In this case, the lock cover 4 should be opened by using a jig.
Accordingly, an essential object of the present invention is to provide, with a view to eliminating the above described drawbacks of conventional branch joint boxes, a branch joint box in which a dummy cover connector is not required to be provided and a female connector can be fitted into a male connector regardless of whether a lock cover is disposed at an open position or a closed position.
In order to accomplish this object of the present invention, a branch joint box in which after a female connector connected to a wiring harness has been fitted into a male connector provided on the branch joint box, a lock cover provided on the branch joint box is closed and the female connector is locked to the male connector at a fitting position of the female connector by a locking portion of the lock cover, according to the present invention comprises: a temporary retention means for temporarily retaining the lock cover to the branch joint box at a closed position of the lock cover prior to fitting of the female connector into the male connector; a temporary retention cancelling means for cancelling temporary retention of the lock cover in response to fitting action of the female connector into the male connector so as to set the lock cover to an open position of the lock cover, and a fixed retention means which, after the female connector has been fitted into the male connector, not only locks the female connector to the male connector but locks the lock cover to the branch joint box.
In the present invention, the lock cover is temporarily retained to the branch joint box at the closed position preliminarily. Then, when the female connector is fitted into the male connector at an assembly line of motor vehicles, temporary retention of the lock cover is cancelled by fitting action of the female connector into the male connector such that the lock cover is automatically opened to the open position. Subsequently, when the lock cover is pushed to the closed position, not only the female connector is locked to the male connector at the fitting position by the locking portion of the lock cover but the lock cover is held at the closed position relative to the branch joint box.